1. Field of the Invention
The present invention relates generally to gas springs. In particular, the present invention is a gas spring with a latching stop mechanism for use on skid-steer loader vehicles.
2. Description of the Prior Art
Skid-steer loaders are popular and in widespread use. The operator's compartment of vehicles of this type is typically enclosed by a cab enclosure such as that illustrated in the Albright et al U.S. Pat. No. 4,408,672. The cab enclosure shown in the Albright et al patent is pivotably secured to the vehicle frame so that it can be raised to a tilt-back position to provide a service technician with better access to components contained with the interior frame of the structure. In the embodiment shown, a torsion spring serves as a mechanical assist for the technician rotating the cab enclosure backwards. A latch mechanism which includes a latch member, spring, and cam, restrains the cab enclosure from forward movement when latched in its tilt-back position.
Gas springs are sometimes used in addition or as an alternative to the torsion spring shown in the Albright et al patent. Gas springs are well known and commercially available from a number of different manufacturers including Suspa Inc. and Gas Spring Corporation. Gas springs with mechanical lock or latching mechanisms are also known and are disclosed, for example, in the Nicholls U.S. Pat. No. 3,883,126, Molders U.S. Pat. No. 4,078,779, Hasegawa U.S. Pat. No. 4,449,702. The Howard U.S. Pat. No. 4,596,383 also discloses a gas spring with a mechanical stop. Mechanical stops of this type cause an eccentric load on the gas spring. Although this may not be a problem when the spring is used to support light loads, it can be a problem with heavier loads which can cause the gas spring to buckle. A stroke-limiting stop for a positioning device is also disclosed in the Porter U.S. Pat. No. 4,155,433.
There is a continuing need for gas springs with improved latch mechanisms. A latch mechanism which can be integrally mounted to the gas spring is desired. The latch mechanism should also linearly load the gas spring. The latch mechanism must, of course, be reliable and convenient to use.